[0001] The present invention relates to aqueous-based autoxidisably crosslinkable coating
compositions, their preparation and use in forming films and coatings.
[0002] Autoxidisably crosslinkable polymers are polymers which crosslink on exposure to
oxygen. It is known that polymers which contain unsaturated fatty acid residues undergo
crosslinking by autoxidation. The unsaturation in polymers from such groups imparts
latent crosslinkability so that when a coating composition thereof is dried in air
(often in conjunction with a drier salt) the composition undergoes crosslinking, thereby
improving its properties such as mechanical properties (improved hardness and durability)
and chemical resistance. A further advantage of coatings containing unsaturated fatty
acid residues is an improved glossy appearance.
EP 379007,
EP 0017199 and
EP 647655 all describe one component emulsions which contain autoxidisable polymers having
carboxylic acid functional groups to provide water dispersability.
[0003] However disadvantages of autoxidisably crosslinkable polymers containing unsaturated
fatty acid residues are that the curing process is slow (typically taking a period
of days) and that yellowing of the coating occurs in time.
[0004] It is known, in for example in
US 4108811 and
WO 97/26303, to blend autoxidisably crosslinkable polymers with acrylic polymer dispersions to
reduce yellowing and in some cases cost, however the performance of the resulting
coatings, in particular the mechanical properties and the resistance to chemicals
is greatly reduced.
US 5559192 discloses a composition containing an autoxidisable polymer and an acetoacetate functional
vinyl polymer however the acetoacetate functional groups do not take part in any crosslinking
of the composition.
WO 2000-24837 discloses an aqueous coating composition comprising at least one polyurethane / acrylate
hybrid dispersion and at least one dispersion of a polyurethane resin with oxidatively
drying groups.
EP 0649865 discloses an aqueous coating composition comprising polyhydrazides and dispersions
of carbonyl-containing polyurethane-vinyl hybrid dispersions.
[0005] We have surprisingly found that compositions of autoxidisably crosslinkable polymers
containing unsaturated fatty acid residues with a polymer which is not autoxidisably
crosslinkable, but has certain other crosslinking means, not only reduces the cure
time and yellowing of coatings derived from such a composition, but also that the
performance of such a composition in other respects (such as the mechanical properties
and chemical resistance) is not vitiated and is comparable to an improvement to the
performance of the autoxidisable crosslinkable polymer containing unsaturated fatty
acid residues alone.
[0006] According to the present invention there is provided an aqueous crosslinkable coating
composition comprising as aqueous dispersed components:
i) at least one autoxidisably crosslinkable organic polymer containing unsaturated
fatty acid residues, and
ii) at least one vinyl polymer which is not autoxidisably crosslinkable and bears
acetoacetyl functional groups, and
wherein said composition has present therein acetoacetyl-reactive amine and/or hydrazine
functional groups which impart crosslinkability to component (ii);
wherein the functional amine or hydrazine groups are provided by polyamines or polyhydrazines
which are not part of the autoxidisably crosslinkable organic polymer or of the vinyl
polymer; and
where the not autoxidisably crosslinkable vinyl polymer is not grafted to the autoxidisably
crosslinkable polymer.
[0007] By an acetoacetyl functional group in this specification is meant a group having
the formula:
where the methyl group may optionally be mono, di or tri-substituted (for example
so as to provide therewith a higher alkyl group of 2 to 10 carbon atoms, usually 2
to 4 carbon atoms) and the methylene group may optionally be monosubstituted (usually
by alkyl of 1 to 4 carbon atoms, particularly methyl). The methyl group could also,
in principle, be replaced by other groups such as a cyclic phenyl group, or an optionally
substituted heterocyclic group, and the use of such alternative groups are also considered
to provide acetoacetyl functional groups for the purpose of this specification. A
polymer-bound acetoacetyl functional group will normally be provided in the environment
of an acetoacetate grouping of formula:
or an acetoacetamide grouping of formula:
or a 1,3 diketone grouping of formula:
where R
1 is hydrogen or a monovalent hydrocarbyl radical such as an (optionally substituted)
alkyl, aryl, aralkyl or alkaryl radical (usually of 1 to 10, particularly 1 to 6 carbon
atoms) and R
2 is a divalent hydrocarbyl radical such as an (optionally substituted) alkylene,
arylene, aralkylene or alkarylene radical (usually of 1 to 20, particularly 1 to 10
carbon atoms).
[0008] Suitable optional substituents for the groups represented by R
1 and R
2 and for the methyl or methylene groups of Formulae (1) to (4) may be selected from
-CN, C
1-4-alkoxy, phenyl, halogen such as -F, -Cl and -Br and C
1-4-alkyl.
[0009] It is preferred, however, that the acetoacetyl functional group is provided by an
acetoacetate or acetoacetamide group, and more preferably by an acetoacetate group.
[0010] By a hydrazine functional group is meant an acetoacetyl-reactive functional group
of formula -NHNH
2 and also an acetoacetyl-reactive hydrazone group derived from such a group by reaction
with a monoketone or monoaldehyde of at least two carbon atoms. It will become apparent
that such functional groups are usually part of larger groups, such as those of formulae,
-R-C(=O)-NH-NH
2, -R-C(=O)-NH-N=C<, -R-NH-C(=O)-NH-NH
2, -R-NH-C(=O)-NH-N=C<, and -R-NH-NH
2 where R is optionally substituted alkylene, optionally substituted alicyclic, or
optionally substituted aryl.
[0011] By an amine functional group is meant an acetoacetyl-reactive group of formula -NH
2, -NH- and acetoacetyl-reactive groups derived from such groups. Examples of amine
functional groups include R-NH
2, R-O-NH
2, R-O-N=C<, -R-NH-C(=O)-O-N=C< and -R-NH-C(=O)-O-NH
2 where R is as described above.
[0012] By an autoxidisably crosslinkable polymer is meant a polymer which crosslinks on
exposure to oxygen from air by virtue of containing unsaturated fatty acid residues.
[0013] By a not autoxidisably crosslinkable polymer is meant a polymer not containing unsaturated
fatty acid residues.
[0014] For the purposes of this invention an "aqueous dispersion" of a polymer(s) means
a dispersion of a polymer(s) in a liquid carrier medium of which water is the principle
component (at least 50 weight %, more usually at least 80 weight %, or the carrier
medium). Minor amounts of organic liquids may optionally be present. The dispersion
will typically comprise colloidally dispersed particles of the polymer(s), i.e. will
typically be in the form of an aqueous latex(ices).
[0015] Preferably the autoxidisably crosslinkable organic polymer containing unsaturated
fatty acid residues is a polyurethane polymer. Other suitable polymers include alkyds
which may be self-emulsifiable, water-based or emulsified alkyds.
[0016] In the invention composition, the acetoacetyl-reactive amine and/or hydrazine functional
groups impart crosslinkability to the vinyl polymer(s) of component (ii) by virtue
of the latter bearing acetoacetyl functional groups. It is nevertheless within the
scope of the invention, albeit less preferred, for such amine and/or hydrazine functional
groups to also impart crosslinkability to the polymer(s) of component (i) if this
polymer(s) also bears acetoacetyl-functional groups - as is possible, but less preferred.
[0017] The disposition of the amine and/or hydrazine functional groups in the invention
composition to impart crosslinkability as defined may be realised in various ways.
More preferably amine functional groups are used in the invention composition.
[0018] The acetoacetyl-reactive amine and/or hydrazine functional groups are present in
the composition by virtue of being provided by added discrete compounds bearing 2
or more amine groups, hereinafter called polyamines, or 2 or more hydrazine functional
groups, hereinafter called polyhydrazines. By "discrete" is meant that such compounds
are exclusive of the polymers of components (i) and (ii). Preferably the polyamines
or polyhydrazines are diamines or triamines (i.e. having 2 or 3 amine groups) or dihydrazines
(i.e. having 2 hydrazine functional groups).
[0019] The presence of such a polyamine or polyhydrazine will impart crosslinkability to
the vinyl polymer(s) of component (ii). However, if the polymer(s) of component (i)
also bears acetoacetyl functional groups (as is possible as discussed above), such
a polyamine or polyhydrazine will also impart crosslinkability to this polymer(s)
of component (i) by reaction with the acetoacetyl functional groups thereof, i.e.
in addition to crosslinkability by autoxidation.
[0020] In the most preferred embodiment, the amine and/or hydrazine groups are present only
in discrete added polyamines and/or polyhydrazines and the acetoacetyl functional
groups are present only in the vinyl polymer(s) of component (ii).
[0021] Autoxidisably crosslinkable polyurethane polymers containing unsaturated fatty acid
residues are preferably obtained from the reaction of at least one organic polyisocyanate
with at least one isocyanate reactive organic compound bearing unsaturated fatty acid
residue(s), optionally (but preferably) with isocyanate-reactive organic compounds
bearing water-dispersing groups, and in some embodiments (as implied above), isocyanate-reactive
compounds bearing carbonyl and/or carbonyl-reactive amine or hydrazine groups. Optionally,
the reactants may also include a low molecular weight isocyanate-reactive compound(s)
(preferably with a molecular weight below 500), usually an organic polyol and/or a
high molecular isocyanate-reactive compound(s) (preferably with a molecular weight
of from 500 to 6000), also usually an organic polyol - such compounds, if used, bearing
neither unsaturated fatty acid residues nor water-dispersing groups. Isocyanate-reactive
groups include -OH, -NH-, and -NH
2.
[0022] The polyurethane polymer may be prepared in a conventional manner by reacting the
organic polyisocyanate(s) with a stoichiometric equivalent amount of isocyanate-reactive
compounds.
[0023] The polyurethane polymer may be prepared in a conventional manner by reacting the
organic polyisocyanate(s) with the isocyanate-reactive compound(s) by methods well
known in the prior art. Preferably an isocyanate-terminated polyurethane prepolymer
is first formed, which is chain extended with an active hydrogen containing compound.
If the Polymer is made in such manner, the unsaturated fatty acid residue bearing
compound is introduced into the polyurethane backbone during the prepolymer formation
and/or during the chain extension step. The optional polymer-based carbonyl, amine
or hydrazine groups (see supra) may also be introduced during the prepolymer formation
and/or during the chain extension step.
[0024] Alternatively a polyurethane (preferably of a low molecular weight) may be made by
capping an isocyanate-terminated polyurethane with monofunctional isocyanate-reactive
compounds or by using an excess of compounds having isocyanate-reactive groups during
polymer preparation, or a combination of the above preparations may be used.
[0025] Optionally (but preferably) monomer(s) bearing non-ionic or ionic water-dispersing
or emulsifier groups (or groups that may be subsequently converted thereto) are included
in the prepolymer formation to provide the facility of self-dispersability in water
of the polyurethane prepolymer and the final autoxidisably crosslinkable polyurethane
polymer.
[0026] Preferred isocyanate-reactive compounds bearing unsaturated fatty acid residue(s)
which may be used in the urethane synthesis may be obtained from the reaction, using
techniques known in the art of a suitable fatty acid with a hydroxyl donor (preferably
an alcohol or polyol) or amine donor to provide a fatty acid residue-bearing compound
with at least one (preferably at least two) hydroxyl or amine isocyanate-reactive
groups.
[0027] Preferred fatty acids include fatty acids derived from castor oil, soyabean oil,
sunflower oil, tallow oil, linseed oil and fatty acids such as linoleic acid, palmitoleic
acid, linolenic acid, oleic acid, oleosteric acid, licanic acid, arachidonic acid,
ricinoleic acid and/or mixtures thereof.
[0028] Suitable polyisocyanates include aliphatic, cycloaliphatic, araliphatic and/or aromatic
polyisocyanates. Examples of suitable polyisocyanates include ethylene diisocyanate,
1-6-hexamethylene diisocyanate, isophorone diisocyanate, cyclohexane-1, 4-diisocyanate,
4,4'-dicyclohexylmethane diisocyanate, p-xylylene diisocyanate, tetramethylxylene
diisocyanate, 1,4-phenylene diisocyanate, 2-4-toluene diisocyanate, 2,6-toluene diisocyanate,
4,4'-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 2,4'-diphenylmethane
diisocyanate, 3(4)-isocyanatomethyl-1-methyl cyclohexyl isocyanate (IMCI) and polymethylene
polyphenyl polyisocyanates. Mixtures of polyisocyanates can be used and also polyisocyanates
which have been modified by the introduction of urethane, allophanate, urea, biuret,
carbodiimide, uretonimine, urethdion or isocyanurate residues.
[0029] Other isocyanate-reactive organic compounds bearing neither unsaturated fatty acid
residues nor water-dispersing groups (see supra) which may be used in the preparation
of polyurethanes or polyurethane prepolymers preferably containing at least one (preferably
at least two) isocyanate-reactive groups, and are more preferably organic polyols.
The organic polyols particularly include diols and triols and mixtures thereof but
higher functionality polyols may be used, for examples as minor components in admixture
with diols. The polyols may be members of any of the chemical classes of polyols used
or proposed to be used in polyurethane formulations. In particular the polyols may
be polyesters, polyesteramides, polyethers, polythioethers, polycarbonates, polyacetals,
polyolefins or polysiloxanes. Preferred polyol molecular weights are from 250 to 6000,
more preferably from 500 to 3000. Low molecular weight organic compounds containing
at least one (preferably at least two) isocyanate-reactive groups and having a weight
average molecular weight of up to 500, preferably in the range of 40 to 250 can also
be used. Examples include ethylene glycol, 1-propanol and 1,4-cyclohexyldimethanol.
[0030] The water-dispersing group content of the polyurethane (if present) may vary within
wide limits but should be sufficient to provide the polyurethane with the required
degree of water-dispersibility.
[0031] Water-dispersing groups are optionally incorporated into the polyurethane by including
an isocyanate-reactive and/or isocyanate compound(s) bearing nonionic and/or ionic
water-dispersing groups (or groups which may be subsequently converted to such water-dispersing
groups) as reactants in the preparation of the polymer or prepolymer.
[0032] Typically, ionic water-dispersing groups are anionic salt groups, for example carboxylate,
sulphonate and phosphonate salt groups. Examples of such compounds include carboxy
group containing diols and triols, for example dihydroxy alkanoic acids. The preferred
carboxy containing diol is 2,2-dimethylolpropionic acid or 2,2-dimethylolbutanoic
acid. If desired, the carboxy containing diol or triol may be incorporated into a
polyester by reaction with a dicarboxylic acid before being incorporated into the
prepolymer. The conversion of any acid groups present in the prepolymer to anionic
salt groups may be effected by neutralising the said acidic groups before, after or
simultaneously with formation of an aqueous dispersion of the prepolymer.
[0033] Non-ionic water-dispersing groups are preferably pendant polyoxyalkylene groups,
particularly polyoxyethylene groups.
[0034] The polyurethane polymer or prepolymer may have a combination of ionic dispersing
groups and non-ionic water-dispersing groups.
[0035] Optionally a carbonyl functional group (such as a ketone or aldehyde group) may be
introduced onto a polyurethane backbone by using for example carbonyl functional compounds
with at least one and preferably two isocyanate-reactive groups, for example dihydroxyketones.
[0036] When an isocyanate-terminated polyurethane prepolymer is prepared, it is conventionally
formed by reacting a stoichiometric excess of the organic polyisocyanate with the
isocyanate-reactive compounds as hereinbefore described under substantially anhydrous
conditions at a temperature between about 30°C and about 130°C until reaction between
the isocyanate groups and the isocyanate-reactive groups is substantially complete;
the reactants for the prepolymer are generally used in proportions corresponding to
a ratio of isocyanate groups to isocyanate-reactive groups of from about 1.1:1 to
about 6:1, preferably from about 1.5:1 to 3:1.
[0037] If desired, catalysts such as dibutyltin dilaurate and stannous octoate, zirconium
or titanium based catalysts may be used to assist prepolymer formation. An organic
solvent may optionally be added before or after prepolymer formation to control the
viscosity Examples of solvents include water-miscible solvents such as N-methylpyrrolidone,
dimethyl sulphoxide and dialkyl ethers of glycol acetates or mixtures of N-methylpyrrolidone
and methyl ethyl ketone. Optionally no organic solvents are added.
[0038] An aqueous polyurethane dispersion may then be prepared by dispersing the isocyanate-terminated
polyurethane prepolymer (optionally carried in an organic solvent medium) in an aqueous
medium (using surfactants, or more preferably by utilising the self-dispersability
of the prepolymer if dispersing groups are present therein, although surfactants may
still be employed if desired) and chain extending the prepolymer with active hydrogen-containing
chain extender in the aqueous phase.
[0039] The aqueous polyurethane dispersion may of course comprise more than one polyurethane
polymer prepared as defined above.
[0040] The urethane prepolymer may be dispersed in water using techniques well known in
the art. Preferably, the prepolymer is added to the water with agitation or, alternatively,
water may be stirred into the prepolymer.
[0041] Active hydrogen-containing chain extenders which may be reacted with the prepolymer
include polyol(s), amino-alcohol(s), a primary or secondary diamine(s) or polyamine(s),
hydrazine(s) or a substituted hydrazine(s).
[0042] Examples of such chain extenders useful herein include alkylene diamines such as
ethylene diamine and cyclic amines such as isophorone diamine. Also materials such
as hydrazine, azines such as acetone azine, substituted hydrazines such as, for example,
dimethyl hydrazine, 1,6-hexamethylene-bis-hydrazine, carbodihydrazine, hydrazides
of dicarboxylic acids and sulphonic acids such as adipic acid mono- or dihydrazide,
oxalic acid dihydrazide, isophthalic acid dihydrazide, hydrazides made by reacting
lactones with hydrazine such as gammahydroxylbutyric hydrazide, bis-semi-carbazide,
and bis-hydrazide carbonic esters of glycols may be useful. Water itself may be effective
as an indirect chain extender.
[0043] Where the chain extender is other than water, for example a polyol, polyamine or
hydrazine, it may be added to the aqueous dispersion of prepolymer or, alternatively,
it may already be present in the aqueous medium when the prepolymer is dispersed therein.
The prepolymer may also be chain extended to form the polyurethane polymer while dissolved
in organic solvent (usually acetone) followed by the addition of water to the polymer
solution until water becomes the continuous phase and the subsequent removal of the
solvent by distillation to form an aqueous dispersion.
[0044] The chain extension can be conducted at elevated, reduced or ambient temperatures.
Convenient temperatures are from about 5°C to 95°C or, more preferably, from about
10°C to 60°C.
[0045] The total amount of chain extender materials employed (apart from water) should be
such that the ratio of active hydrogens in the chain extender(s) to isocyanate groups
in the prepolymer preferably being in the range from 0.1:1 to 2.0:1 more preferably
0.80:1 to 1.7:1.
[0046] The not autoxidisably crosslinkable vinyl polymers bearing acetoacetyl functional
groups of component (ii) may be formed by the free-radical addition polymerisation
of at least one acetoacetyl functional group containing monoethylenically unsaturated
monomer with at least one other olefinically unsaturated monomer not providing acetoacetyl
functionality.
[0047] Suitable olefinically unsaturated monomers which bear acetoacetyl functional groups
include acetoacetic acid esters and amides of hydroxyalkylacrylates, hydroxyalkylmethacrylates
and hydroxy alkenes. The alkyl group in any of the hydroxyalkyl-acrylates or -methacrylates
is preferably a C
1-10-alkyl group each of which may be a straight or branched chain. The alkene group in
the hydroxyalkene is preferably a C
2-10-alkene, more preferably a C
2-6-alkene and especially a C
3-alkene group.
[0048] Preferred olefinically unsaturated monomers bearing acetoacetyl functional groups
include acetoacetic acid esters and amides of hydroxyethylacrylate, hydroxypropylacrylate,
hydroxyethylmethacrylate, hydroxypropylmethacrylate and ally alcohol.
[0049] Especially preferred acetoacetyl functional group containing unsaturated monomers
include acetoacetoxyethyl methacrylate (AAEM), acetoacetoxyethyl acrylate, acetoacetoxypropyl
methacrylate, allyacetoacetate, acetoacetoxybutyl methacrylate, 2,3-di(acetoacetoxy)propyl
methacrylate and 2-acetoamido-2-methylpropyl methacrylate.
[0050] Acetoacetyl functional group containing unsaturated monomers can be prepared by reacting
unsaturated hydroxy functional monomers with diketones or other acetoacetylating agents.
[0051] The proportion of acetoacetyl functional groups in the vinyl polymer is preferably
2 to 200 milliequivalents per 100g of polymer, more preferably 5 to 100 milliequievalents
per 100g of polymer.
[0052] Examples of non-acetoacetyl-providing olefinically unsaturated monomers include 1,3-butadiene,
isoprene, styrene, divinyl benzene, acrylonitrile, methacrylonitrile, vinyl halides
(such as vinyl chloride), vinyl esters (such as vinyl acetate, vinyl propionate and
vinyl laurate), heterocyclic vinyl compounds, alkyl esters of monolefinically unsaturated
dicarboxylic acids (such as di-n-butyl maleate and di-n-butyl fumarate) and, in particular,
esters, of acrylic acid and methacrylic acid, examples of which are methyl acrylate,
methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl
methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isopropyl acrylate,
hydroxyethylmethacrylate, hydroxypropylmethacrylate, isopropyl methacrylate, n-propyl
acrylate and n-propyl methacrylate.
[0053] Examples of monoaldehyde or monoketone-containing unsaturated monomers include acrolein,
methacrolein, diacetone-acrylamide, crotonaldehyde, 4-vinylbenzaldehyde, vinyl alkyl
ketones of 4 to 7 carbon atoms such as vinyl methyl ketone, and acryloxy- and methacryloxy-alkyl
propanols. Further examples include acrylamidopivalaldehyde, methacrylamidopivalaldehyde,
3-acrylamidomethylanisaldehyde, diacetone acrylate and diacetone methacrylate.
[0054] Olefinically unsaturated monomers bearing anionic water-dispersing groups may also
be used, examples of which include acrylic acid, methacrylic acid, itaconic acid and/or
maleic acid.
[0055] Olefinically unsaturated monomers having non-ionic water-dispersing groups such as
alkoxy polyethylene glycol methacrylates may also be used.
[0056] A vinyl polymer bearing acetoacetyl functional groups may be prepared by any suitable
free-radical initiated polymerisation technique, a free-radical initiator and appropriate
heating (e.g. 40°C to 90°C) being employed. The polymerisation is normally effected
in an aqueous medium, and in particular aqueous emulsion polymerisation is used to
prepare the polymer with optionally conventional dispersants being used. Free radical
initiators include hydrogen peroxide, t-butylhydroperoxide, persulphates such as NH
4 persulphate K persulphate and Na persulphate or a redox system may be used.
[0057] Not autoxidisably crosslinkable vinyl polymers bearing acetoacetyl functional groups
for use in the invention preferably have a weight average molecular weight within
the range 1000 to 5,000,000 (more usually 2,000 to 1,000,000). The weight average
molecular weight may be measured by gel permeation chromatography (gpc).
[0058] Polyhydrazines or polyamines used to crosslink acetoacetyl or optional carbonyl functional
groups present in the composition are, incorporated into components (i) and/or (ii)
before mixing the components or after or during the mixing of components (i) and (ii),
as discrete entities.
[0059] Preferred polyhydrazines include but are not limited to dicarboxylic acid bis-hydrazides,
bis-hydrazones, specific examples being oxalic acid dihydrazide, malonic acid dihydrazide,
succinic acid dihydrazide, adipic acid dihydrazide, and sebacic acid dihydrazide,
cyclohexane dicarboxylic acid bis-hydrazides, azelaic acid bis-hydrazides; also carbonic
acid hydrazides, bis-semicarbazides, trihydrazides, dihydrazinoalkones and dihydrazines
of aromatic hydrocarbons, for example 1,4-dihydrazinobenzene and 2,3-dihydrazinonophthalene,
dihydrazine and others known in the art. Preferred examples include adipic acid dihydrazide
and carbonic acid dihydrazides.
[0060] Preferred polyamines include but are not limited to those with primary and/or secondary
amino groups having from 2 to 10 such amino groups per molecule especially preferred
are primary amines. Suitable examples include ethylenediamine, propylenediamine, decamethylene
diamine, 1,2-diaminocyclohexane, isophoronediamine, 4-amino-1,8-octanediamine urea,
N-(2-hydroxyethyl)ethylenediamine, tris(2-aminoethyl) amine, melamine, diethylenetriamine,
dipropylenetriamine, dibutylenetriamine, polyethylene imines, and Jeffamine, (polyoxyethylene
amines available from Huntsman Corporation, Houston, Texas).
[0061] Discrete polyamines or polyhydrazines are added to the composition, the level is
preferably that to provide a range of 0.02 to 1.6 moles more preferably 0.05 to 0.9
moles of amine or hydrazine groups present per mole of acetoacetyl functional groups
present in the composition.
[0062] Component (ii), in addition to the at least one not autoxidisably crosslinkable vinyl
polymer bearing acetoacetyl groups may optionally comprise a further not autoxidisably
crosslinkable polymer or polymer moiety. Suitable not autoxidisably crosslinkable
polymers include vinyl polymers not bearing acetoacetyl functional groups, polyurethane
polymers not bearing acetoacetyl functional groups and/or polyurethane polymers bearing
acetoacetyl functional groups.
[0063] Preferably the additional not autoxidisably crosslinkable polymer is a polyurethane
polymer or polyurethane polymer moiety.
[0064] If a not autoxidisably crosslinkable polyurethane polymer is included in the composition
as part of component (ii) (see later) it may be made in the same manner as the autoxidisably
crosslinkable polyurethane as described above but without the introduction of unsaturated
fatty acid residue bearing compounds.
[0065] The additional not autoxidisably crosslinkable polymer or polymer moiety is a) optionally
a discrete polymer (i.e. not covalently bonded to the not autoxidisably crosslinkable
vinyl polymer bearing acetoacetyl functional groups), b) formed by
in-situ polymerisation in the presence of the at least one non-autoxidisably crosslinkable
vinyl polymer bearing acetoacetyl functional groups. Alternatively the not autoxidisably
crosslinkable vinyl polymer bearing acetoacetyl functional groups is formed by
in-situ polymerisation in the presence of the additional polymer.
[0066] Alternatively the additional polymer may comprise a copolymerised moiety of the not
autoxidisably crosslinkable vinyl polymer bearing acetoacetyl functional groups.
[0067] The autoxidisably crosslinkable polymer of component (i) and the not autoxidisably
crosslinkable polymer(s) of component (ii) of the composition of the invention may
be brought together by any suitable technique.
[0068] For example an aqueous dispersion of component (i) and an aqueous dispersion of component
(ii) may be mixed together with agitation. The aqueous solution may also contain water-miscible
organic solvents.
[0069] Alternatively the not autoxidisably crosslinkable vinyl polymer may be prepared in
the presence of the autoxidisably crosslinkable polymer (component (i)). For example
free-radical initiators may be added to a dispersed mixture of component (i) and vinyl
monomer(s) or
vice versa and polymerisation of the vinyl polymer effected.
[0070] The weight ratio of organic polymer(s) of component (i) to the not autoxidisably
crosslinkable vinyl polymer bearing acetoacetyl functional groups in the composition
is suitably in the range from 90 : 10 to 10 : 90 more preferably of from 70 : 30 to
30 : 70.
[0071] Preferred pH ranges are 4 to 11, more preferably 6.5 to 9.5 and especially 7 to 8.5.
[0072] Neutralisation agents which may be applied include organic bases, for example hydroxides
of lithium, sodium or potassium, and organic bases for example ammonia or tertiary
amines for example dimethyl ethanol amine and triethyl amine morpholine.
[0073] It is preferred to store the invention composition in a closed container, where due
to the low amount of oxygen no significant crosslinking of the autoxidisable polymer
has been found to occur until after application. However, this is by no means always
necessary and indeed it is possible to use the invention composition soon after its
production.
[0074] After coating the composition the water evaporates, oxygen in the atmosphere initiates
autoxidisation and a dual crosslinking reaction takes place.
[0075] The aqueous composition of the invention may be advantageously employed as coating
compositions, (e.g. protective or adhesive coating compositions) for which purpose
they may be further diluted with water and/or organic solvents, or they may be supplied
in more concentrated form by evaporation of water and/or organic components of the
liquid medium. As coating compositions, they may be applied to any substrate including
wood, metals, glass, cloth, leather, paper, plastics, foam and the like, by any conventional
method including brushing, dipping, flow coating, spraying, and the like.
[0076] Drier salts preferably comprise part of the composition. Examples include polyvalent
salts containing cobalt, calcium, copper, zinc, iron, zirconium and manganese as the
cation and halides, nitrates, sulphates, acetates, napthenates or acetoacetonates
as the anion. The amount of drier used is in the range from 0 to 1% metal content
by weight of the composition. The compositions may contain other conventional ingredients
including organic solvents, pigments, dyes, emulsifiers, surfactants, thickeners,
heat stabilisers, levelling agents, anti-cratering agents, fillers, sedimentation
inhibitors, UV absorbers, antioxidants, waxes and the like introduced at any stage
of the production process or subsequently. It is possible to include an amount of
an antimony oxide in the dispersions to enhance the fire retardant properties. The
dispersions may also be used as adhesives for materials such as polypropylene, polyester,
polyurethane, leather and the like or as binding agents for various particulate materials.
[0077] The dispersions suitably have a solids contents of from about 20 to 60% by weight,
preferably from about 25 to 45% by weight.
[0078] If desired, the compositions of the present invention may include other polymer dispersions
for example polyurethane, polyamide, polyepoxide, polyvinyl acetate, polyethylene,
polystyrene, polybutadiene, polyvinyl chloride, polyacrylate and other homopolymer
and copolymer dispersions. These can sometimes be prepared in-situ (for example by
polymerisation of the monomers in the presence of the polyurethane polymer or prepolymer).
[0079] The weight ratio of the organic polymer of component (i) and the not autoxidisably
crosslinkable vinyl polymer(s) bearing acetoacetyl functional groups to other polymers
included in the composition is preferably from 100:00 to 40:60, more preferably 100:00
to 70:30, most preferably 100:0.
[0080] There is still further provided according to the invention a coated substrate having
a coating obtainable or derived from an aqueous crosslinkable coating composition
comprising a polymer dispersion as defined above, and the use of such a composition
for coating a substrate.
[0081] The present invention is now illustrated by the following examples. Unless otherwise
specified, all parts and percentages are on a weight basis.
Preparation of autoxidisably crosslinkable organic polymers containing unsaturated
fatty acid residues = FATTY ACIDS 1-5
FATTY ACID 1
An unsaturated fatty acid residue containing urethane dispersion.
Stage 1 - Synthesis of a fatty acid residue containing polyester polyol for incorporation
into a polyurethane
[0082]
Components |
Ingredients |
parts by weight |
1 |
Adipic acid |
535.9 |
2 |
"Prifac" 8960 (a polyunsaturated fatty acid from Unichema) |
916.0 |
3 |
1,4-Cyclohexane dimethanol |
250.5 |
4 |
Trimethylolpropane |
411.7 |
5 |
Fascat 2005 (SnCl2) |
0.1 |
6 |
Cardura E10 (Neodecanoic acid glycidyl ester) |
97.7 |
7 |
N,N- dimethylbenzylamine |
1.9 |
[0083] Components 1, 2, 3 and 4 were charged to a 2.5 litre flask fitted with a stirrer,
condenser, nitrogen inlet and thermocouple. The resultant mixture was gradually heated
to the reaction temperature of 215 °C. Water of distillation was collected. At this
reaction temperature component 5 was added and the mixture was esterified until an
acid value of 10.4 mg KOH/g was obtained. Subsequently the temperature was reduced
to 170°C and components 6 and 7 were added and reacted until an acid value of 0.1
mg KOH/g was obtained. The total reaction time was 12 hours. The hydroxyl value of
the polyester polyol was 76.8 mg KOH/g.
Stage 2 - Synthesis of a fatty acid residue containing polyurethane prepolymer
[0084] An isocyanate terminated urethane prepolymer containing the polyester polyol prepared
in Stage 1 was prepared as described below:
[0085] 269.6g of Desmodur W (4,4'-dicyclohexylmethane diisocyanate), 34.0 g of a difunctional
isocyanate-reactive non-ionic component with a joint hydroxy number and acid number
of 87 and a polypropylene oxide/ethylene (PO/EO) ratio of 9/1, 34.0 g dimethylol propionic
acid (DMPA), 342.4 g of the polyester polyol from stage 1 and 120.0g of N-methylpyrrolidone
(NMP) were added to a 1 litre 3 necked round bottom flask. The mixture was stirred
under nitrogen. The mixture was heated to 55 C and 4 drops of Dabco T-9 (a tin octoate
catalyst from Air Products) were added. The mixture was then heated to 95°C and kept
at this temperature for 1 hour. 4 drops of Dabco T-9 were added and the mixture was
kept at 95°C for another hour. 8.7g sample was taken for NCO determination. The residual
NCO content was 5.05%. The batch was cooled down to 75°C.
[0086] 25.6g of triethylamine (TEA) and 10.2 g of Dapro 5005 (manganese drier salt) were
added to the prepolymer. The mixture was kept at this temperature for 40 minutes.
Stage 3 - Preparation of a polyurethane dispersion from the polyurethane prepolymer
prepared in Stage 2.
[0087] 600.0 g of the prepolymer prepared in Stage 2 was added to a waterphase consisting
of 820.7 g demineralised water and 19.6 g of Atlas G-4809 a non-ionic alkoxylated
alkylphenol surfactant (70%). The total addition time was 65 minutes. The prepolymer
was kept at 70-75°C during the addition to the waterphase, the temperature of the
waterphase was 30-32°C.
[0088] When the addition was complete, a mixture of 15.6 g of hydrazine hydrate (63.7%)
and 25 g of demineralised water was added to the dispersion. The temperature of the
dispersion increased to 40°C and was kept at this temperature for 30 minutes. The
batch was cooled to room temperature and sieved through a 200 mesh sieving cloth.
[0089] The dispersion had a solids content of 35%, pH of 8.1, viscosity of 210 mPas at 25°C
and a sediment content of <0.05%.
FATTY ACID 2
A fatty acid residue containing low molecular weight (non chain extended) polyurethane
Stage 1 - Preparation of amide ester diol products from soyabean oil.
[0090] A reactor was charged with 148.8g diethanotamine and 1.2g sodium methoxide and the
mixture was heated to 90-100°C until all of the sodium methoxide had dissolved.
[0091] Subsequently, 750g soyabean oil (available from Alnor Oil company) was added to the
mixture followed by stirring and heating to 105-110°C for 4.5 hours.
[0092] Gel Permeation Chromatography (GPC) of the amide ester diol product showed its composition
to consist of 10.7% unreacted soyabean oil, 41.5% dtglyceride mono-ol and 47.8% monogtyceride
amide diol (ester amide polyol). The theoretical hydroxy equivalent weight of the
amide ester diol product was 211 and corresponding OH number was 266 mg KOH/g.
Stage 2 - Preparation of a uralkyd resin
[0093] 116.3g of the amide ester diol product from Stage 1 was mixed in a reactor with 18g
2,2-dimethylolpropionic acid, 12.8g cyclohexanedimethanol, 20.3g methoxypolyethyleneoxide
glycol (MPEG750), 134.2 g N-methylpyrrolidone, and 118.3g toluene diisocyanate. The
temperature was maintained at 50-60°C for one hour. Then more amide ester diol product
(133.7g) was added and the temperature increased to 70-80°C for two hours.
Stage 3 - Preparation of an aqueous uralkyd resin dispersion
[0094] The product from Stage 2 was diluted with 76.7g dipropylene glycol monomethyl ether
(acting as a cosolvent to reduce viscosity) and 9.55g dimethylethanolamine dissolved
in 187g water (base for neutralising carboxyl groups). 5.6 g Drier salt (Dapro 5005
available from Daniels Products) followed by 520 g water at 60°C was added to the
mixture while stirring.
[0095] The resulting dispersion had a clear, transparent yellow colour with a viscosity
of 1640 mPa.s at 25°C, a pH of 7.1 and solids content of 31%.
FATTY ACID 3
An autoxidisably crosslinkable polyester containing unsaturated fatty acid residues
[0096] Worléesol 31A (available from Worlée-Chemie GmbH) is an anionically stabilised alkyd
resin containing unsaturated fatty acid residues, neutralised with ammonia and is
supplied as a solution in a water/butylglycol mixture (80/20). The resin has a solid
content of 45.9%, a viscosity at 20°C of 127 s (according to DIN 53211), the acid
number on solids is 100.3 mg KOH/g and pH is 7.8. This solution was used as supplied.
FATTY ACID 4
An autoxidisably crosslinkable urethane dispersion containing unsaturated fatty acid
residues
[0097] NeoRez R2001 (available from NeoResins, Avecia BV) is a chain extended urethane dispersion
containing unsaturated fatty acid residues. The fatty acid content is approximately
35% on solids. The dispersion has a solids content of 34.9%, pH was 7.8 and the viscosity
was 220 mPa.s. This dispersion was used as supplied. (NeoRez and NeoResins are Trade
Marks of Avecia bv).
Synthesis of not autoxidisably crosslinkable vinyl dispersions bearing acetoacetyl
functional groups = NAVP's 6 to 9
NAVP 6
A not autoxidsably crosslinkable acrylic dispersion bearing acetoacetyl functional
groups
[0098] 912 g of demineralised water and 1.82 g of sodium lauryl sulphate (30% w/w) were
added to a three necked round bottom flask, equipped with a thermometer, stirrer,
cooler and a N
2 inlet. The mixture was heated to 70°C under N
2 atmosphere.
[0099] 5 % of a monomer mixture consisting of 188.2 g of demineralised water, 5.45 g of
sodium lauryl sulphate (30% w/w), 7.0g of lauryl mercaptane, 3.5 g of mercapto propionic
acid, 34.9 g of acetoacetoxyethyl methacrylate (AAEM), 43.6 g of methacrylic acid
and 357.6 g of methylmethacrylate was added to the reactor. The reactor content was
then heated to 80°C.
[0100] 30% of a solution of ammonium persulphate (87.2g, 1.5% w/w) in water was added to
the reactor. The reactor content was heated to 85°C and mixed at this temperature
for 5 minutes.
[0101] The remainder of the monomer mixture was added to the reactor after 60 minutes, and
the remainder of the ammonium persulphate solution was added to the reactor after
70 minutes. The reactor content was kept at 85°C during this period. After the addition
was complete, the reactor content was held at 85°C for another 30 minutes.
[0102] A solution of 34.5 g of ammonia (25% w/w) and 124.4 g of demineralised water was
added to the reactor. The reactor content was held at 85°C for another 20 minutes.
After this the batch was cooled down to room temperature and sieved through a 200
mesh sieve cloth. The pH was 7.8 and the viscosity was 4 mPas at 25°C.
[0103] 1034.5 g of this polymer dispersion was mixed with 195.4 g of demineralised water
for 15 minutes at room temperature. 0.22 g of dimethylethanol amine and 160.8 g of
butylmethacrylate and 45.2 g of butylacrylate, and 6.4g of AAEM were added to the
reactor, followed by 1.84 g of tert.-butylhydroperoxide (30% solution in water w/w)
and 2.8 g of a 1% (w/w) solution of iron ethylene diamine tetraacetate (FeEDTA) in
water. The reactor content was heated to 35°C and mixed for 60 minutes.
[0104] 2.7 g of a 3.96% (w/w) solution of i-ascorbic acid in water was added and the temperature
of the reactor content increased to 53°C. The batch was held at this temperature for
15 minutes.
[0105] Then 40.0 g of a 1.21% (w/w) solution of i-ascorbic acid in water was added to the
reactor in 30 minutes at 53°C. The batch was mixed for 15 minutes and cooled down
to 35°C.
[0106] A mixture of dimethylethanol amine (0.22 g), butyl methacrylate (160.8 g) AAEM (6.38
g) and butyl acrylate (45.2 g) was added to the reactor. 1.84 g of tert.-butylhydroperoxide
(30% solution in water w/w), 2.86 g of a 1% (w/w) solution of FeEDTA in water and
235.8 g of demineralised water were added to the reactor and mixed for 60 minutes
at 35°C. 2.7 g of a 3.96% (w/w) solution of i-ascorbic acid in water was added to
the reactor content. The temperature of the batch increased to 48°C and was mixed
at this temperature for 15 minutes.
[0107] Then 37.0 g of a 1.21% (w/w) solution of i-ascorbic acid in water was added to the
reactor in 30 minutes at 47°C.
[0108] The batch was mixed for 30 minutes at 47°C, and a solution of crosslinker and demineralised
water was added before mixing for a further 30 minutes at 47°C, cooled down to room
temperature and sieved through a 200 mesh sieve cloth.
[0109] The specifications of this batch were as follows: solids content 34.7%, pH of 8.1
and viscosity of 86 mPas at 25°C. To 1000g of this dispersion was added 7.2 g of Jeffamine
T-403 (a polyoxyethylene amine available from Huntsman Corporation, Houston, Texas)
and 6.7 g of demineralised water. The pH of the dispersion was 8.7 and the viscosity
77 mPas at 25°C.
NAVP 7
A not autoxidisably crosslinkable acrylic dispersion bearing acetoacetyl functional
groups
[0110] 859.8 g of demineralised water, 14.0 g of sodium lauryl sulphate (30w/w), 1.69 g
ammonium persulphate and 1.03 g of ammonium bicarbonate (25% w/w) were added to a
three necked round bottom ftask, equipped with a thermometer, stirrer, cooler and
a N
2 inlet. 10% of a monomer mixture consisting of 242.0 g of demineralised water, 28.1
g of sodium tauryl sulphate (30% w/w), 2.53 g ammonium persulphate, 2 g ammonium bicarbonate
(25% w/w), 50.5 g acetoacetoxy ethyl methacrylate, 33.7 g methacrylic acid, 421.2
g butylmethacrylate, 142.6 g butylacrylate and 194.3 g styrene was added to the reactor.
This mixture was heated to 80°C under N
2 atmosphere and mixed at this temperature for 20 minutes. The remainder of the monomer
mixture was added to the reactor over a period of 90 minutes. The reactor content
was kept at 80°C during this period. After the addition was complete, the reactor
content was held at 80°C for another 30 minutes. A solution of 3.08 g of ammonia (25%
w/w) and 3.34 g of demineralised water was added to the reactor. The reactor content
was held at 80°C for another 30 minutes. After this the batch was cooled down to room
temperature and sieved through a 200 mesh sieve cloth. The pH was 6.3 and the viscosity
was 43 mPa.s at 25°C. To 1000 g of this dispersion 4.8 g of 4-(aminomethyl)-1,8-octane
diamine (available from BASF) was added as crosslinker.
NAVP 8
A not autoxidisably crosslinkable acrylic dispersion bearing acetoacetyl functional
groups
[0111] 859.8 g of demineralised water, 14.0 g of sodium lauryl sulphate (30w/w), 1.69 g
ammonium persulphate and 1.03 g of ammonium bicarbonate (25% w/w) were added to a
three necked round bottom flask, equipped with a thermometer, stirrer, cooler and
a N
2 inlet. 10% of a monomer mixture consisting of 242.0 g of demineralised water, 28.1
g of sodium lauryl sulphate (30% w/w), 2.53 g ammonium persulphate, 2 g ammonium bicarbonate
(25% w/w), 25.3 g acetoacetoxy ethyl methacrylate, 33.7 g methacrylic acid, 421.2
g butylmethacrylate, 154.3 g butylacrylate and 207.9 g styrene was added to the reactor.
This mixture was heated to 80°C under N
2 atmosphere and mixed at this temperature for 20 minutes. The remainder of the monomer
mixture was added to the reactor over a period of 90 minutes. The reactor content
was kept at 80°C during this period. After the addition was complete, the reactor
content was held at 80°C for another 30 minutes. A solution of 3.08 g of ammonia (25%
w/w) and 3.34 g of demineralised water was added to the reactor. The reactor content
was held at 80°C for another 30 minutes. After this the batch was cooled down to room
temperature and sieved through a 200 mesh sieve cloth. The pH was 6.5 and the viscosity
was 49 mPa.s at 25°C. To 1000 g of this dispersion 2.4 g of 4-(aminomethyl)-1,8-octane
diamine (available from BASF) was added as crosslinker.
NAVP 9: A non-autoxidisably crosslinkable urethane-acrylic hybrid bearing acetoacetyl
functional groups in the acrylic polymer
Stage 1 - Synthesis of a polyurethane prepolymer
[0112] An isocyanate terminated urethane prepolymer was prepared as described below: 632
g IPDI (isophorone diisocyanate), 88 g dimethylol propanoic acid (DMPA), 880 g of
a polypropylene glycol diol with an average molecular weight of 1600 g/mole (OH number
= 77.4 mg KOH/g) and 4 drops of Dabco T-9 (a tinoctoate catalyst from Air Products)
were added to a 2 litre 3 necked round bottom flask. The mixture was stirred under
nitrogen and heated to 95°C and kept at this temperature until the practical NCO content
reached 7.7% (g NCO/ g prepolymer). The batch was cooled down to 70°C. 54.8 g TEA
was added to the prepolymer and the mixture was kept at this temperature for 1 hour.
Stage 2 - Preparation of a polyurethane dispersion from the polyurethane prepolymer
prepared in Stage 1
[0113] 650 g of prepolymer prepared in Stage 1 was added to a water phase consisting of
977.9 g demineralised water and 16.25 g of the surfactant Synperonic NP9 (available
from ICI Surfactants). The total addition time was 70 minutes.
When the addition was complete, a mixture of 27.0 g of hydrazine hydrate (63.5%) and
27 g water was added to the dispersion. The temperature of the dispersion increased
to 41°C and was kept at this temperature for 30 minutes. The batch was cooled down
to room temperature and sieved through a 200 mesh sieving cloth.
The dispersion had a solids content of 39%, pH was 7.4 and viscosity at 25°C was 160
mPa.s.
Stage 3 - Synthesis of a not autoxidisably crosslinkable urethane-acrylic hybrid bearing
acetoacetyl functional groups from the polyurethane dispersion of Stage 2
[0114] 55.6 g butyl methacrylate, 12.2 g methyl methacrylate, 10.1 g acetoacetoxy ethyl
methacrylate and 130 g demineralised water were added to 400 g of polyurethane dispersion
from Stage 2 and slowly heated to 36°C. Then 0.35 g of a Fe(II)EDTA solution (1% w/w
in water), 5.1 g of a tertiary butyl hydroperoxide solution (4.7% w/w in water) and
22.6 g iso-ascorbic acid solution (1% w/w in water) was added. The temperature was
increased to 48°C and was kept on this temperature for 18 minutes and cooled to room
temperature. 55.6 g butyl methacrylate, 12.2 g methyl methacrylate, 10.1 g acetoacetoxy
ethyl methacrylate and 130 g demineralised water were subsequently added and slowly
heated to 31 °C and 22.6 g iso-ascorbic acid solution (1% w/w in water) was added.
The temperature was increased to 35°C and 11.3 g iso-ascorbic acid solution (1% w/w
in water) was added and kept on this temperature for 13 minutes and again 11.3 g iso-ascorbic
acid solution (1% w/w in water) was added and temperature was kept on 32 °C for 1
hour. The resulting urethane-acrylic hybrid dispersion was cooled down to room temperature
and sieved through a 200 mesh sieving cloth. The dispersion had a solids content of
35.2%, pH was 7.8 and viscosity at 25°C was 40 mPa.s. To 400 g of this dispersion
1.7 g 4-(aminomethyl)-1,8-octane diamine (available from BASF) was added as a crosslinker
together with 20 g surfactant Akyporox 111-400V (available from Kao Chemicals GmbH).
Comparative vinyl polymers
Preparation of not autoxidisably crosslinkable vinyl polymers not bearing acetocetyl
functional groups = CVP's 10 to 12
CVP 10
A not autoxidsably crosslinkable acrylic dispersion not bearing acetoacetyl functional
groups
[0115] 911.86 g of demineralised water and 1.82 g of sodium lauryl sulphate (30% w/w) were
added to a three necked round bottom flask, equipped with a thermometer, stirrer,
cooler and a N
2 inlet. The mixture was heated to 70°C under N
2 atmosphere.
[0116] 5% of a monomer mixture consisting of 188.2 g of demineralised water, 5.45 g of sodium
lauryl sulphate, 6.98 g of lauryl mercaptane, 3.49 g of mercapto propionic acid, 43.61
g of methacrylic acid and 392.44 g of methylmethacrylate was added to the reactor.
The reactor content was then heated to 80°C.
[0117] 30% of a solution of ammonium persulphate (87.2g, 1.5% w/w) in water was added to
the reactor. The reactor content was heated to 85°C and mixed at this temperature
for 5 minutes.
[0118] The remainder of the monomer mixture was added to the reactor after 60 minutes, the
remainder of the ammonium persulphate solution was added to the reactor after 70 minutes.
The reactor content was kept at 85°C during this period. After the addition was complete,
the reactor content was held at 85°C for another 30 minutes.
[0119] A solution of 34.50 g of ammonia (25% w/w) and 124.4 g of demineralised water was
added to the reactor. The reactor content was held at 85°C for another 20 minutes.
After this the batch was cooled down to room temperature and sieved through a 200
mesh sieve cloth. The pH was 8.3 and the viscosity was 12 mPas at 25°C.
[0120] 1055.60g of this polymer dispersion was mixed with 184.15 g of demineralised water
for 15 minutes at room temperature. 0.22 g of dimethylethanol amine and 170.34 g of
butylmethacrylate and 46.55 g of butylacrylate were added to the reactor, followed
by 1.88 g of tert.-butylhydroperoxide (30% solution in water w/w) and 2.86 g of a
1% (w/w) solution of iron ethylene diamine tetraacetate (FeEDTA) in water. The reactor
content was heated to 35°C and mixed for 60 minutes.
[0121] 2.75g of a 3.96% (w/w) solution of i-ascorbic acid in water was added and the reactor
content was heated to 57°C in 25 minutes. The batch was held at this temperature for
15 minutes.
[0122] Then 37.75 g of a 1.21% (w/w) solution of i-ascorbic acid in water was added to the
reactor in 30 minutes at 57 C. The batch was mixed for 15 minutes and cooled down
to 35°C.
[0123] A mixture of dimethylethanol amine (0.22 g), butyl methacrylate (170.4 g) and butyl
acrylate (46.5 g) was added to the reactor. 1.88 g of tert.-butylhydroperoxide (30%
solution in water w/w), 2.86 g of a 1% (w/w) solution of FeEDTA in water and 235.77
g of demineralised water were added to the reactor and mixed for 60 minutes at 35°C.
2.75 g of a 3.96% (w/w) solution of i-ascorbic acid in water was added to the reactor
content. The batch was heated to 42°C and mixed at this temperature for 15 minutes.
[0124] Then 37.75 g of a 1.21% (w/w) solution of i-ascorbic acid in water was added to the
reactor in 30 minutes at 42°C.
[0125] The batch was mixed for 30 minutes at 40°C, cooled down to room temperature and sieved
through a 200 mesh sieve cloth.
[0126] The specifications of this batch were as follows: solids content 35%, pH of 7.9 and
viscosity of 24 mPas at 25°C.
CVP 11
A not autoxidisably crosslinkable acrylic dispersion not bearing acetoacetyl functional
groups
[0127] 859.8 g of demineralised water, 14.0 g of sodium lauryl sulphate (30w/w), 1.69 g
ammonium persulphate and 1.03 g of ammonium bicarbonate (25% w/w) were added to a
three necked round bottom flask, equipped with a thermometer, stirrer, cooler and
a N
2 inlet. 10% of a monomer mixture consisting of 242.0 g of demineralised water, 28.1
g of sodium lauryl sulphate (30% w/w), 2.53 g ammonium persulphate, 2 g ammonium bicarbonate
(25% w/w), 33.7 g methacrylic acid, 421.2 g butylmethacrylate, 166.1 g butylacrylate
and 221.4 g styrene was added to the reactor. This mixture was heated to 80°C under
N
2 atmosphere and mixed at this temperature for 20 minutes. The remainder of the monomer
mixture was added to the reactor during 90 minutes. The reactor content was kept at
80°C during this period. After the addition was complete, the reactor content was
held at 80°C for another 30 minutes. A solution of 3.08 g of ammonia (25% w/w) and
3.34 g of demineralised water was added to the reactor. The reactor content was held
at 80°C for another 30 minutes. After this the batch was cooled down to room temperature
and sieved through a 200 mesh sieve cloth. The pH was 6.5 and the viscosity was 36
mPa.s at 25°C. To 1000 g of this dispersion 2.4 g of 4-(aminomethyl)-1,8-octane diamine
(available from BASF in Germany) was added.
CVP 12
A not autoxidisably crosslinkable urethane-acrylic hybrid dispersion not bearing acetoacetyl
functional groups
[0128] 66.6 g butyl methacrylate, 11.5 g methyl methacrylate and 130 g demineralised water
were added to 400 g of polyurethane dispersion from stage 2 from Example 10 and slowly
heated to 35°C. Then 0.35 g of a Fe(II)EDTA solution (1% w/w in water), 5.1 g of a
tertiary butyl hydroperoxide solution (4.7% w/w in water) and 22.6 g iso-ascorbic
acid solution (1% w/w in water) was added. The temperature was increased to 44°C and
was kept on this temperature for 18 minutes and cooled to room temperature.
66.6 g butyl methacrylate, 11.5 g methyl methacrylate and 130 g demineralised water
were subsequently added and slowly heated to 34 °C and 22.6 g iso-ascorbic acid solution
(1% w/w in water) was added. 11.3 g iso-ascorbic acid solution (1% w/w in water) was
added and kept on this temperature for 13 minutes and again 11.3 g iso-ascorbic acid
solution (1% w/w in water) was added and temperature was kept on 33 °C for 1 hour.
The resulting urethane-acrylic hybrid dispersion was cooled down to room temperature
and sieved through a 200 mesh sieving cloth. The dispersion had a solids content of
35%, pH was 8.2 and the viscosity at 25°C was 50 mPa.s. To 400 g of this dispersion
1.7 g 4-(aminomethyl)-1,8-octane diamine (available from BASF) was added, together
with 20 g surfactant Akyporox 111-400V (available from Kao Chemicals GmbH).
Examples 1 to 30 and Comparative Examples CE1 to CE25:
[0129] Preparation of compositions according to the invention were carried out by blending
at room temperature the autoxidisably crosslinkable organic polymers containing unsaturated
fatty acid residues [FATTY ACIDS 1 to 5] prepared as described above with the not
autoxidisably, crosslinkable vinyl polymers bearing acetoacetyl functional groups
NAVP's 6 to 9 prepared as described above. Comparative examples CE1 To CE25 were prepared
by blending at room temperature the autoxidisably crosslinkable organic polymers bearing
unsaturated fatty acid residues [FATTY ACIDS 1 to 5] with not autoxidisably crosslinkable
vinyl polymers not bearing acetoacetyl functional groups [CVP's 10 to 12]. The composition
and the properties of resultant coatings are shown in Tables 1 to 6.
i) Resistance The blends were cast down on Leneta testcharts Form 2C with a film thickness of 100
µm. The films were dried at room temperature for 20 minutes and at 50°C for 64 hours.
After they were cooled down to room temperature the films were tested for "household
chemical resistance".
a) Drops of the various testing liquids (water, ethanol, coffee and "Andy" a commonly
used Dutch detergent) were placed on the films and covered with a watch glass. The
liquids were removed after 16 hours at room temperature and the damage to the coating
was assessed immediately and after four hours recovery. 0 Means that the coating was
dissolved, 5 means that the coating was not affected at all.
b) For the hot pan test a drop of boiling water was placed on the film and covered
with a beaker containing boiling water for one hour before immediate assessment of
the coating. 0 means that the coating was dissolved, 5 means that the coating was
not affected at all.
ii) BHMR = Black heel mark resistance: the coating was hit with a black heel and the degree
of damage to the coating was assessed the same as the household chemical resistance
is assessed.
iii) Yellowness (= Yellow): 0 is very yellow, 5 is a colourless coating.
iv) Hardness Development: The Hardness was measured using a Pendulum Hardness Tester according to the König
test method. The larger the value, the harder the film was.
v) Pencil hardness: was measured according to ASTM D3363-929 and H numbers are hard and B numbers are
soft on a scale from 8H to HB to B or less.
Examples 1 and 2: Blends of FATTY ACID 1 and NAVP 6 and Comparative Examples CE1 to
CE5: FATTY ACID 1, NAVP 6, CVP 10 and blends of FATTY ACID 1 AND CVP 10
[0130]
Table 1
Example |
vinyl polymers |
FATTY ACID 1/ vinyl polymers ratio (w/w) |
BHMR |
Yellow |
Stain resistances (assessment after 4 hrs) |
|
|
|
|
|
Water |
EtOH |
Coffee |
Andy |
CE1 |
None |
100/0 |
5 |
0 |
5* |
5 |
5* |
5 |
4* |
4 |
5* |
5 |
CE2 |
CVP 10 |
0/100 |
1 |
5 |
5* |
5 |
2* |
2 |
4* |
4 |
1* |
1 |
CE3 |
NAVP 6 |
0/100 |
1 |
5 |
3* |
3 |
4* |
4 |
5* |
5 |
4* |
4 |
CE4 |
CVP 10 |
50/50 |
2 |
2 |
5* |
5 |
1* |
1 |
4* |
4 |
2* |
3 |
1 |
NAVP 6 |
50/50 |
2 |
2 |
5* |
5 |
4* |
5 |
4* |
5 |
4* |
5 |
CE5 |
CUP 10 |
25/75 |
1 |
0 |
5* |
5 |
1* |
1 |
5* |
5 |
0* |
0 |
2 |
NAVP 6 |
25/75 |
1 |
5 |
5* |
5 |
4* |
5 |
4* |
5 |
5* |
5 |
* = immediate assessment before recovery |
Examples 3 to 8: Blends of FATTY ACID 1 with NAVP 7, NAVP 8 and NAVP 9 and Comparative
Examples CE6 to CE9: Blends of FATTY ACID 1 with CVP 11 and CVP 12
[0131]
Table 2
Example |
vinyl polymers |
FATTY ACID 1/ vinyl polymers ratio (w/w) |
BHMR |
Stain resistances
(assessment after 4 hrs) |
Hardness Development (room temperature) |
|
|
|
|
Water |
EtOH |
Coffee |
Andy |
3 hrs |
6 hrs |
1 day |
2 days |
3 |
NAVP 7 |
25/75 |
4 |
5 |
5 |
2 |
4-5 |
10 |
14 |
49 |
56 |
4 |
NAVP 7 |
50/50 |
4-5 |
5 |
5 |
4 |
4 |
17 |
27 |
51 |
61 |
5 |
NAVP 8 |
25/75 |
4-5 |
5 |
5 |
4 |
5 |
10 |
16 |
51 |
59 |
6 |
NAVP 8 |
50/50 |
3 |
5 |
4 |
3-4 |
3 |
20 |
30 |
54 |
63 |
CE6 |
CVP 11 |
25/75 |
0 |
5 |
4 |
3 |
5 |
11 |
15 |
46 |
49 |
CE7 |
CVP 11 |
50/50 |
0 |
5 |
2 |
4 |
4 |
16 |
26 |
47 |
59 |
|
|
|
|
|
|
|
|
3hrs |
5hrs |
7hrs |
4 days |
7 |
NAVP 9 |
|
4 |
5 |
4 |
0-1 |
5 |
50 |
57 |
69 |
67 |
8 |
NAVP 9 |
25/75 |
5 |
5 |
4 |
0-1 |
5 |
57 |
63 |
69 |
67 |
CE8 |
CVP 12 |
|
0 |
5 |
3-4 |
1 |
5 |
54 |
60 |
69 |
64 |
CE9 |
CVP 12 |
25/75 |
0 |
4 |
3 |
0-1 |
3-4 |
50 |
56 |
57 |
56 |
Examples 9 to 14: Blends of FATTY ACID 2 with NAVP 7, NAVP 8 and NAVP 9 and Comparative
Examples CE10 to CE13: Blends of FATTY ACID 2 with CVP 11 and CVP 12
[0132]
Table 3
Example |
vinyl polymers |
FATTY ACID 4/ vinyl polymer ratio (w/w) |
BHMR |
Stain resistances
(assessment after 4 hrs) |
Hardness Development (room temperature) |
|
|
|
|
Water |
EtOH |
Coffee |
Andy |
3 hrs |
6 hrs |
1 day |
2 days |
9 |
NAVP 7 |
50/50 |
3-4 |
4 |
1 |
3 |
2 |
tacky |
9 |
63 |
90 |
10 |
NAVP 7 |
25/75 |
3 |
4-5 |
4 |
2-3 |
3-4 |
9 |
14 |
46 |
80 |
11 |
NAVP 8 |
50/50 |
3 |
4 |
3 |
2-3 |
3 |
tacky |
10 |
59 |
80 |
12 |
NAVP 8 |
25/75 |
3 |
5 |
3 |
2-3 |
3 |
tacky |
7 |
39 |
57 |
CE10 |
CVP 11 |
50/50 |
0 |
2 |
1 |
2 |
3 |
tacky |
9 |
34 |
74 |
CE11 |
CVP 11 |
25/75 |
0 |
1-2 |
1 |
2 |
2 |
tacky |
9 |
50 |
64 |
13 |
NAVP 9 |
50/50 |
3-4 |
5 |
4 |
1 |
4-5 |
23 |
29 |
37 |
- |
14 |
NAVP 9 |
25/75 |
1 |
4 |
4 |
0-1 |
4 |
31 |
36 |
40 |
- |
CE12 |
CVP 12 |
50/50 |
0 |
5 |
3 |
0-1 |
4 |
23 |
29 |
36 |
- |
CE13 |
CVP 12 |
25/75 |
0-1 |
4 |
3 |
0-1 |
3 |
29 |
31 |
37 |
- |
- = not measured |
Examples 15 to 18: Blends of FATTY ACID 3 and NAVP 7 and NAVP 9 and Comparative Examples
CE14 to CE17: Blends of FATTY ACID 1 and CVP 11 and CVP12
[0133]
Table 4
Example |
vinyl polymers |
FATTY ACID 3/ vinyl polymer ratio (w/w) |
BHMR |
Stain resistances
(assessment after 4 hrs) |
Hardness Development (room temperature) |
|
|
|
|
Water |
EtOH |
Coffee |
Andy |
3 hrs |
6 hrs |
1 day |
15 |
NAVP 7 |
25/75 |
3-4 |
5 |
5 |
2 |
4 |
4 |
4 |
10 |
16 |
NAVP 7 |
50/50 |
0 |
2 |
1 |
1 |
1 |
tacky |
tacky |
tacky |
CE14 |
CVP 11 |
25/75 |
0 |
5 |
3 |
2 |
3 |
tacky |
tacky |
tacky |
CE15 |
CVP 11 |
50/50 |
0 |
1 |
1 |
1 |
1 |
tacky |
tacky |
tacky |
17 |
NAVP 9 |
50/50 |
0 |
3 |
3 |
1 |
2 |
11 |
11 |
11 |
18 |
NAVP 9 |
25/75 |
4 |
4 |
3-4 |
0-1 |
0 |
17 |
17 |
17 |
CE16 |
CVP 12 |
50/50 |
0 |
5 |
4 |
1 |
2 |
14 |
14 |
14 |
CE17 |
CVP 12 |
25/75 |
0 |
4-5 |
3 |
0-1 |
3 |
19 |
19 |
19 |
Examples 19 to 24: Blends of FATTY ACID 4 with NAVP 7, NAVP 8 and NAVP 9 and Comparative
Examples CE18 to CE21: Blends of FATTY ACID 4 and CVP 11 and CVP 12
[0134]
Table 5
Example |
vinyl polymers |
FATTY ACID 4/ vinyl polymer ratio (w/w) |
BHMR |
Stain resistances
(assessment after 4 hrs) |
Hardness Development (room temperature) |
|
|
|
|
hot pan |
EtOH |
Coffee |
Andy |
4 hrs |
1 day |
2 days |
19 |
NAVP 7 |
50/50 |
5 |
4-5 |
4-5 |
5 |
4-5 |
13 |
33 |
54 |
20 |
NAVP 7 |
25/75 |
4-5 |
2 |
4-5 |
3-4 |
4 |
9 |
26 |
40 |
21 |
NAVP 8 |
50/50 |
4-5 |
4 |
5 |
5 |
5 |
10 |
29 |
47 |
22 |
NAVP 8 |
25/75 |
4 |
3-4 |
5 |
4 |
5 |
6 |
20 |
33 |
CE18 |
CVP 11 |
50/50 |
0 |
4 |
5 |
5 |
5 |
10 |
26 |
44 |
CE19 |
CVP 11 |
25/75 |
0 |
4 |
3 |
4 |
5 |
7 |
19 |
36 |
|
|
|
|
Water |
EtOH |
Coffee |
Andy |
3hrs |
6hrs |
1 day |
23 |
NAVP 9 |
50/50 |
5 |
5 |
4 |
1 |
5 |
43 |
56 |
71 |
24 |
NAVP 9 |
25/75 |
5 |
5 |
4 |
1 |
5 |
49 |
54 |
60 |
CE20 |
CVP 12 |
50/50 |
1 |
4 |
2 |
1 |
4-5 |
59 |
63 |
70 |
CE21 |
CVP 12 |
25/75 |
0 |
4-5 |
4 |
0-1 |
5 |
50 |
53 |
59 |
Examples 25 to 30: Blends of FATTY ACID 5 with NAVP 7, NAVP 8 and NAVP 9 and Comparative
Examples CE22 to CE25: Blends of FATTY ACID 5 and CVP 11 and CVP 12
[0135]
Table 6
Example |
vinyl polymers |
FATTY ACID 5/ vinyl polymer ratio (w/w) |
BHMR |
Stain resistances
(assessment 4 hrs after recovery) |
Hardness Development (room temperature) |
|
|
|
|
Water |
EtOH |
Coffee |
Andy |
3 hrs |
6 hrs |
1 day |
4 days |
25 |
NAVP 7 |
50/50 |
3-4 |
5 |
3 |
2-3 |
3-4 |
17 |
33 |
69 |
89 |
26 |
NAVP 7 |
25/75 |
4 |
2 |
4 |
4 |
4 |
13 |
29 |
66 |
81 |
27 |
NAVP 8 |
50/50 |
2 |
5 |
4-5 |
2 |
2 |
14 |
26 |
59 |
81 |
28 |
NAVP 8 |
25/75 |
2-3 |
0 |
3 |
2-3 |
2-3 |
11 |
21 |
46 |
64 |
CE22 |
CVP11 |
50/50 |
0-1 |
1 |
1 |
2 |
0-1 |
16 |
29 |
49 |
61 |
CE23 |
CVP11 |
25/75 |
0 |
0 |
2 |
2-3 |
0 |
10 |
23 |
49 |
61 |
29 |
NAVP 9 |
50/50 |
3 |
5 |
4 |
1 |
5 |
43 |
50 |
54 |
59 |
30 |
NAVP 9 |
25/75 |
4 |
5 |
4 |
0-1 |
5 |
46 |
50 |
50 |
54 |
CE24 |
CVP 12 |
50/50 |
1 |
3-4 |
2 |
1 |
5 |
46 |
53 |
61 |
63 |
CE25 |
CVP 12 |
25/75 |
1 |
5 |
3 |
0-1 |
5 |
49 |
53 |
59 |
59 |